Fabrication of an autonomously self-healing flexible thin-film capacitor by slot-die coating

Abstract

Flexible pressure sensors with self-healing abilities for wearable electronics are being developed, but generally either lack autonomous self-healing properties or require sophisticated material processing methods. To address this challenge, we developed flexible, low-cost and autonomously self-healing capacitive sensors using a crosslinked poly(dimethylsiloxane) through metal–ligand interactions processed into thin films via slot-die coating. These films have excellent self-healing properties, approximately 1.34 × 10⁵ μm³ per hour at room temperature and 2.87 × 10⁵ μm³ per hour at body temperature (37 °C). Similarly, no significant change in capacitance under bending strain was observed on these flexible thin-films when assembled on poly(ethyleneterephthalate) (PET) substrates; capacitors showed good sensitivity at low pressure regimes. More importantly, the devices fully recovered their sensitivity after being damaged and healed, which is directly attributed to the rapid and autonomous self-healing of the dielectric materials.